Clare Balding tells the story of football’s best kept secret. A century ago it was women who ruled the pitch. A team of working class girls became footballs biggest stars. They would challenge convention to take on a man’s world - commanding crowds bigger than the men’s game of up to 60,000 fans. But then, on the 5th of December 1921, the FA placed a complete ban on women playing professional football. That ban was to last 50 years. This is the story of the factory girls who took on the world, a journey to discover why they were banned and find out the legacy of that ban 100 years on.